In the construction of swimming pools with relatively vast amounts of concrete decking, it is common to conduct runoff of rain water and/or overflow to a suitable surface level drain fixedly set within the decking at selected locations. The decking surface is normally pitched toward the drain which via its subsurface conduit conveys the drain water to a remote discharge location where the drain water can be disposed of either by dumping on the ground or by connection to an underground conduit. Exemplifying continuous elongated drains of this type are the disclosures of U.S. Pat. Nos. 3,465,654 and 3,876,322.
While the drainage systems disclosed by the foregoing patents have generally functioned well for the purpose of conducting rain runoff from the decking away from the perimeter of the pool, they are known to have proven deficiences that render them troublesome and undesirable from the standpoint of maintenance and service. Typically, the prior art drains of the aforesaid type are constructed almost entirely of polymer plastic composition. The grating area is exposed and comprises an integral part of, or which during installation becomes a permanent part of, the underlying drain trough. In that relation, the trough portion remains buried in the decking, while the surface grating is continuously exposed to sunlight containing ultraviolet light (U.V.). Over a period of several years the U.V. adversely affects the plastic grating composition causing the exposed grating to gradually deteriorate until repair becomes necessary.
Being that the grating is however not per se separately removable, repair can involve removing entire sections of drain including the trough portions and at least the adjacent concrete for which the cost can prove disproportionately prohibitive. For the same reason, cleaning the drain trough of leaves or other debris tending to collect within the trough can prove most difficult if not nearly impossible to perform effectively. That is, without a ready access at various locations along the drain, clean out via the use of conventional implements or even a garden hose for effecting wash down can represent a major hassle in the maintenance of such drains.
Yet another problem has been the adverse effects of expansion and contraction of the decking concrete and soil shifting on the secured drain enabling the drain to function as an expansion joint. It is not uncommon for the secured decking to be strained or crushed beyond its yield limit as the surrounding concrete is caused to contract and expand in response to ambient temperature swings.
Despite recognition of the foregoing, a ready solution therefore had not heretofore been available.